OsABCB14 functions in auxin transport and iron homeostasis in rice (Oryza sativa L.) |
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Authors: | Yanxia Xu Saina Zhang Haipeng Guo Suikang Wang Ligen Xu Chuanyou Li Qian Qian Fan Chen Markus Geisler Yanhua Qi De An Jiang |
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Affiliation: | 1. State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, , Hangzhou, China;2. State Key Laboratory of Plant Genomics, National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, , Beijing, China;3. State Key Laboratory of Rice Biology, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, , Hangzhou, China;4. State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, , Beijing, China;5. Department of Biology – Plant Biology, University of Fribourg, , Fribourg, Switzerland |
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Abstract: | Members of the ATP Binding Cassette B/Multidrug‐Resistance/P–glyco‐protein (ABCB/MDR/PGP) subfamily were shown to function primarily in Oryza sativa (rice) auxin transport; however, none of the rice ABCB transporters have been functionally characterized. Here, we describe that a knock‐down of OsABCB14 confers decreased auxin concentrations and polar auxin transport rates, conferring insensitivity to 2,4‐dichlorophenoxyacetic acid (2,4–D) and indole‐3‐acetic acid (IAA). OsABCB14 displays enhanced specific auxin influx activity in yeast and protoplasts prepared from rice knock‐down alleles. OsABCB14 is localized at the plasma membrane, pointing to an important directionality under physiological conditions. osabcb14 mutants were surprisingly found to be insensitive to iron deficiency treatment (–Fe). Their Fe concentration is higher and upregulation of Fe deficiency‐responsive genes is lower in osabcb14 mutants than in wild‐type rice (Nipponbare, NIP). Taken together, our results strongly support the role of OsABCB14 as an auxin influx transporter involved in Fe homeostasis. The functional characterization of OsABCB14 provides insights in monocot auxin transport and its relationship to Fe nutrition. |
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Keywords: | OsABCB14 polar auxin transport iron homeostasis rice Oryza sativa  L |
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